Lululemon shares are up more than 80 percent over the past 12 months, and one analyst says there's more upside

Yoga pants and leggings maker Lululemon is a bright spot in retail today, with plenty more runway for sales growth, according to one investment bank.

Barclays, in a note to clients this week, is calling out Lululemon's growing share of the athletic apparel market, its increasing investments in men's merchandise like boxer shorts, and unique collaborations — like with fitness chain SoulCycle — as driving momentum for the brand and fueling sales.

The firm still has an overweight rating on Lululemon shares, with a price target of $200, which is almost 38 percent upside from Tuesday's closing price of $144.99.

Lululemon shares have soared more than 80 percent over the past 12 months. And the stock is up nearly 20 percent so far this year, more than double the S&P 500 Retail ETF's (XRT's) growth of about 8.5 percent. Nike shares, for comparison, are up 18 percent year to date. Under Armour shares are up about 22 percent. These two companies in particular are expected to become even closer competitors with Lululemon as it does more to target men.

On Wednesday, Lululemon shares were down less than 1 percent.

At Lululemon, "we see substantial runway for growth across categories, channels and geographies," analyst Matthew McClintock said. "We continue to believe Lululemon's [total addressable market] is ever-expanding as the company has entered into men's in a meaningful way, has seen success in office, travel [and] commute offerings and continues to see a significant amount of opportunity in bras and outerwear."

Showing it's really serious about selling running clothes and yoga gear to guys, Lululemon earlier this month announced that former Eagles quarterback Nick Foles signed a deal with the brand, to become its first men's ambassador.

Lululemon is expected to report fourth-quarter and 2018 earnings after the bell on Wednesday, March 27. Barclays has raised its profit outlook and now expects the retailer to reports fourth-quarter earnings of $1.74 per share, up from $1.64 per share. On Lululemon's upcoming investor day in April 24, Barclays added it expects the company "will outline an ample revenue opportunity but also margin expansion."

By many, Lululemon has been declared a winner of this past holiday season, as shoppers flocked to buy activewear for others and for themselves. Casual gear like jogger pants and knit tops — often referred to as athleisure — are even creeping into workplaces. Goldman Sachs recently relaxed its dress code because of "the changing nature of workplaces generally in favor of a more casual environment."